Circuit breakers controlling an external alarm circuit



y 1965 T. w. COUGHLIN EI'AL 3, 3,

CIRCUIT BREAKERS CONTROLLING AN EXTERNAL ALARM CIRCUIT 2 Sheets-Sheet 1 Filed Aug. 25, 1961 t INVENTORS WaMAas m @UGvVL/M M444 7 A. awav,

W \nkw ATTORNEYS July 6, 1965 T. W. COUGHLIN ETAL CIRCUIT BREAKERS CONTROLLING AN EXTERNAL ALARM CIRCUIT ATTORNEYS United States Patent CIRCUIT BREAKERS CONTROLLING AN EXTERNAL ALARM CIRCUIT Thomas W. Coughlin and William H. Owen, both of Cambridge, Md., assignors to Airpax Electronics Incorporated, Cambridge, Md., a corporation of Maryland Filed Aug. 25, 1961, Ser. No. 134,616 9 Claims. (Cl. 200-106) This invention relates to electrical circuit breakers and more particularly to circuit breakers that are manually set to the on position but which can only be tripped open" in response to overload currents.

It is an object of the invention to provide a circuit breaker which is responsive to overload in an external circuit and also simultaneously controls an external indicator or alarm circuit, the device including contact mechanism that is common to both circuits.

Another object is to provide a circuit breaker controlling two external circuits and automatically operative to open one of the two circuits in response to a predetermined overload condition therein and close the other circuit, the contact mechanism including a movable contact comprising a part of both circuits.

Another object is to provide a circuit breaker controlling both a main and alarm electrical circuits having a contact common to both circuits and in which the main circuit can be closed manually only and automatically tripped open only by a predetermined amount of overload in the main circuit, the alarm circuit being simultaneously actuated.

Another object is to provide a circuit breaker controlling a main external circuit and having a manual member operable onlyfor closing the contacts therefor, the contacts being openable only by and automatically in response to an overload condition in the main circuit and in which the position of the manual member provides a visual indicator of the condition of the circuit breaker.

A further object is to provide an enclosed circuit breaker wherein the manually operable contact closing member constitutes a visual indicator of overload-tripped open contacts in the enclosed circuit breaker.

A further object is the provision of a circuit breaker having control contacts for a main circuit that can be manually actuated only to closed position and including contacts for an indicator circuit that are automatically closed when the main circuit contacts are automatically tripped open by a predetermined amount of current overload.

A further object is the provision of a circuit breaker for a controlled external electrical circuit and having an external electrical alarm or signal circuit, the circuit-closing contacts in the circuit for the two electrical circuits having a contact means common to both external circuits that is operable only to one circuit-controlling position by manual means and automatically operable by overload to another circuit controlling position.

A further object is the provision of a dual-circuit switch mechanism wherein a movable contact is common to both circuits thereby causing one circuit to be automatically closed when the other circuit is automatically opened by a predetermined current overload therein.

A further object is to provide a circuit breaker for dual external circuits wherein thecircuit breaker includes a manual operator effective only to close the contacts of one circuit while opening the contacts of the other circuit, the manual operator further constituting a visual indicator of the condition of both circuits.

A further object is to provide an electromagnetic circuit breaker controlling one or more external circuits wherein the solenoid, contacts and manual actuator of the circuit breaker are disposed in substantial axial alignment to effect minimum dimensional characteristics.

A further object is the provision of a circuit breaker comprised largely of simple and readily available materials rendering it relatively easy and inexpensive to manufacture.

A further object is the provision of a compact and struc turally simple circuit breaker that is sealed against the admission of dust and moisture.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and the accompanying drawings showing a preferred embodiment of the invention in which:

FIGURE 1 is a side elevational view of the circuit breaker with a part broken away and its casing shown in section.

plate portion 1% having an end wall portion 11, extending the full height and width of the structure, and an opposite end wall portion 12 the upper end of which extends the full width of but only a portion of the height of the device. End wall portions 11 and 12 are shown integral with base 10 but obviously may be formed separately and attached thereto. The frame structure F also includes an upper wall plate 13 secured to end wall 11 at its upper end, the plate 13 extending parallel to base plate Ill.

Centrally of the width of end wall 12 is a nonmetallic insulating electromagnetic coil spool 15 of an electromagnet C mounted on a core member 16 having a pole piece 17 wtih a vertically extending face. The core member 16 is mounted on and may be secured to end wall 12 by means of a force fit in wall aperture 18. Disposed opposite each other and symmetrically of pole piece 17 and fixedly mounted in cut-outs 2t! and 21 of base plate 10 are a pair of support members 22 and 23 carrying a rotary shaft 24 extending transversely of base plate 10 in adjustable jewel bearings 25 and 26. An L-shaped armature 36, one arm 31 of which is cooperatively related to the vertical face ofpole piece 17, is rigidly secured to shaft 24 by means of arms 33 and 34 so as to oscillate therewith. The other armature arm 32, which is of appreciably narrower width, extends substantially at right angles to arm 31 and has an abutment member 35 adjustably mounted therein at its outer end, as by a screw thread or the like, extending parallel to armature arm 31 for a purpose hereinafter described. A stop abutment pin 36 depends from upper plate 13 to limit the swing of the armature arm 31 away from pole piece 17 when the magnet is de-energized. To provide adequate clearance for the tilting of armature 30 a clearance aperture 10 of suitable shape may be provided in the portion of base plate 10 directly beneath lower armature arm 32.

Extending downwardly from an intermediate location u? on upper frame plate 13 are transversely aligned and spaced wing members 4d which afford a support for a rotary shaft 42 that is disposed parallel to armature shaft 24. Shaft 42 has rigidly secured thereto, as by means of aligned and spaced wing members 43, a depending contact arm 45 carrying intermediate its length a double contact structure having contact surfaces 46 and 46 that extend, respectively, to each face of the arm. At its lower free end arm 45 has a right-angular abutment portion 47 extending in a direction away from armature 349 for a purpose to be later described. A spring 48 is mounted about shaft 42 and so tensioned as to normally urge contact arm 45 anti-clockwise in FIGURE 1.

Fixedly attached in any suitable manner to a downwardly extending ear on upper frame plate 13, and intermediate pivoted contact arm and the electromagnet spool 15, is a slightly resilient depending arm 51 which constitutes a resilient support for a stationary contact 52 carried at its lower end and positioned for engagement by contact portion 46 on pivoted arm 45 when the arm is swung in one direction. Similarly, at the opposite side of pivoted arm $5 is another stationary contact 53, coplanar with contact 52, carried at the lower end of depending rigid arm 54 suitably secured to another depending ear 55 of frame wall 13, the contact 53 also being engageable with pivoted contact portion 3-6 on arm 45 when the latter is swung in the opposite direction. Stationary contacts 52 and 53 also constitute stops to limit the pivotal movement of pivoted contact arm 45.

A pivoted latching member 69, adapted for latching engagement with the lower end of the pivoted contact arm 45, is mounted on a rotary shaft 61 extending transversely of frame base plate 16 and journalled in the pair of support members 22, 23 on the base plate. Pivoted latching member 6%, carried on shaft 61 by means of aligned ears 62. and 63, has a U-shaped latching end 64 of a considerably reduced width underlying the end of pivoted contact lever 4-5 and with which it is latchably engageable under certain conditions, as later explained. The opposite end of pivoted latch member 66 is planar or flat, as is apparent from the showing in FIGURE 1 and overlies abutment 35 on the armature 30 for engagement thereby. The upstanding lip portion 65 of the U-shaped latch end 6d is beveled at 66 for a purpose to be later described. A biasing spring 67 is coiled around shaft 61 and so held as to bias the pivoted latch member 60 in a counterclockwise direction. An abutment or stop pin 70 mounted in base plate 19 limits counterclockwise rotation of the latch lever 60 under conditions to be described.

Fixedly attached in end wall 11 of the frame 10 is a tubular sleeve and slidably mounted therein is a nonmetallic, manually-operable, contact-setting cylindrical plunger 76, constructed for example of a suitable plastic, having a part-spherical head 77 at its inner end, as is clearly illustrated, which is formed by a relatively deep, sharp-edged annular groove 78 in the plunger periphery. Plunger '76 is further provided with an elongated, flattened or cut-away section 79 extending throughout a major intermediate portion of its cylindrical length, the flattened section 79 having abutment end walls 80 and 80 extending radially of the plunger.

A transversely disposed slot 31 is provided in the wall of tubular sleeve 75 in registry with the flattened section 7 9 of the plunger and a plunger retaining ring 82 extends therein from exteriorly of the sleeve. Ring 82 acts in conjunction with end abutment wall surfaces fitl and 8th of the plunger 76 to limit the extent of sliding plunger movement within the sleeve '75. Plunger 76 terminates exteriorly of the sleeve 75, as shown, with an enlarged button 85 for the application of manual pressure thereto. A compression spring 86 is coiled around plunger 76 between the casing wall 11 and button 35, the spring 86 exerting an outwardly biasing pressure on the plunger, the outward movement of which is limited by the abutment features 80, 82.

As clearly shown in FEGURE 2, a pivoted dog 90 is carried on a pin 91 carried by two transversely extending, parallel and spaced ears 92 on the inner end of plunger sleeve 75. The inner end of dog 90 disposed adjacent the plunger 76 is formed with two camming surfaces 94 and 95 angularly related to each other with the apex disposed asymmetrically of the major axis of the dog and located nearer the side of the dog that faces pivoted contact arm 45. Cam surface 94 of the dog is considerably steeper and shorter than is cam surface 95. The steep slope of the dog cam surface 94 is such that the left-hand edge of the plunger slot 78 is latchingly engaged against it by the pressure of spring 86 due to the direction of its resultant thrust extending down through the axis of pin 9i. Accordingly, since dog 90 is not caused to have any pivotal movement it will therefore hold plunger 76 against movement by the bias of its spring 86 and thus will be in the position shown in FIGURES 1 and 2. The shallow slope of the other cam surface 95 of the dog is such that when it is engaged by plunger head 77, as the plunger is manually slid inwardly of sleeve 75 the axis of the plunger thrust on cam surface 95 will extend to the left of the dog above the axis of its pivot pin 91 (FIGURE 2) and hence the dog will be easily tipped over and permit the free sliding movement of the plunger.

A casing 166 is received in enclosing and sealing relationship around portions 1.0, 12 and 13 of the frame structure to seal it against the entrance of dust and moisture, the end wall fill of the casing having suitably positioned thereon three spaced and insulated terminals 102, 103 and 14M- or binding posts for electrical connections. One end of an electrical conductor wire 105 connected to terminal Hi2 extends to and is coiled on spool 15 thereby forming the energizing electric coil for the electromagnet C, the other end of the wire being soldered or otherwise securely attached to fixed contact 52. Another conductor wire 1% is electrically connected at one end to terminal 163 and at its opposite end to pivoted contact 46-46, this wire being sufiiciently long and flexible so as not to interfere with the free pivotal movement of the pivoted contact arm 45. Another conductor wire 107 is electrically connected at one end to terminal 104 and at its other end to fixed contact The three terminals 1G2, 1&3 and we provide connections for two external circuits, the terminals 102 and 03 being connected to the main circuit to be controlled by the circuit breaker while terminals 163 and 1M- provide connections for an indicator or alarm circuit for the device. It is thus apparent that terminal 103 constitutes a common ground connection for both external circuits.

The device functions in the following manner: Noting FIGURE 3, with the circuit breaker connected into the two electrical external circuits in the manner above described; manual pressure is applied to the button 85 of plunger 76 to slide it to the left against the biasing action of its spring 85 which is thereby compressed. As the plunger head 77 moves past dog 9t), it presses against the lower end portion of pivoted contact arm 45, disengaging contact portion 46' from engagement with sta tionary contact 53, thereby opening the alarm circuit, and moving contact portion 46 of the pivoted contact arm into engagement with resiliently supported stationary contact 52 thereby closing the main circuit to be controlled by the circuit breaker. As the pivoting movement of arm 45 occurs, its lower left end bears against the bevel or cam surface 66 on the latching end 64 of pivoted latch member 69, thereby causing the latter to pivot clockwise or down until the end thereof clears the end of arm 45. Further movement of plunger 76 which at this time has, as previously indicated, engaged contacts 46 and 52, causes a slight deflection of stationary contact 52 to the left, by reason of the resiliency of the latters supporting arm 51, until the latching lip 65 of pivoted member 66 clears the end of arm 2 45. The biasing action of spring s7 on the pivoted latch member 60 causes the latching end 64 to swing upwardly around the end of arm 45 to latchingly engage it. Removal of manual pressure on button 85 permits spring 86 to bias plunger 76 a short distance to theright, as shown in FIGURESI and 2, to a point Where the left edge of the plunger groove 78 latchingly engages dog 90 on its cam surface 94. As apparent from the explanation above, plunger 76 is thereby restrained against any further movement to the right by its spring 86. During the slight and predetermined initial movement of plunger 76 to the right the biasing action of spring 48 maintains pivoted contact arm 45 in engagement with plunger head 77 until the end of arm 45 is restrained against further movement by the solid engagement of stationary contact 52 is maintained in contact with pivoted contact portion 46 on pivoted arm 45 due to the resilient deflection that obtains in the supporting arm 51 for contact 52. Hence, the main external circuit remains closed through contacts 46 and 52.

In the event that current flow in the controlled external circuit connected to terminals 102, 193 exceeds a predetermined amount, such as 120 percent of rated load in the instant embodiment, the increased current fiow causes the magnetornotive force of the electromagnet C to become sufliciently strong to attract armature 3th and rotate it counterclockwise into engagement with its pole piece 17. This causes abutment 35 on the armature to strike the overlying adjacent end of pivoted latch member 60 thereby rotating it clockwise to swing the lip 65 of its latch end 64 down and free it from engagement with the lower end of pivoted contact arm 45. The biasing action of contact arm spring 48 immediately rotatestpivoted contact arm 45 counterclockwise thereby opening the controlled main external circuit at contacts 46, 52 and closing the indicator or alarm circuit by engaging its contacts 46, 52, as shown in FIGURE 3. At the same time the abutment portion 47 of arm 4-5 strikes the outer end portion of dog 90 (FIGURE 2) rotating it counterclockwise. This movement of the dog rotates the'dog cam surface 94 free of the plunger head 77 thereby releasing the plunger 76 for outward movement by the compression in its biasing spring 86 to the position where end abutment wall 80 of flattened section 79 of the plunger engages retaining ring 82 thereby preventing its further outward movement, as shown in FIG- URE 3.

It is thus apparent that not only is an electrical indicator or alarm circuitclosed when an overloading of the control-led main external circuit occurs but also a mechanical visual indicator device is simultaneously actuated, as indicated .by the relative position of themanualsetting button 85 relative to the circuit breaker wall 11. The advantages of this dual system for indicating the open circuit condition of the controlled external circuit are believed clearly obvious. Moreover, the circuit breaker of this invention is foolproof in that the controlled externalcircuit cannot be manually opened after beingmanually closed; it can only be tripped open automatically on the occurrence of a predetermined amount of circuit overload.

While the invention has been shown and described in accordance with the patent statutes it is to be understood that various changes in the details of the structure may be made without departing from the spirit of the inven tion. ,It is desired therefore that the invention be limited only by the scope or the appended claims.

What is claimed is:

1. An electrical circuit breaker comprising frame means having mounted thereon plural stationary contact means, a movable contact means, spring means biasing said movable contact means in one direction, manual means to move said pivoted contact means in the opposite latch lip 65 therewith. Throughout this slight counterclockwise movementof arm 45 by its spring 48 the direction to engage one of said stationary contacts, said spring biased in one direction and engageable with said movable contact means at one end of its movement, motor means in one of said external circuits, said latch means being responsive to overload in the motor means to release said movable contact means to open said one circuit, said biasing means moving said movable contact means when released to close the other of said circuits, said motor means and said movable and plural stationary contact means and said manual means all lying in substantial axial alignment, said movable contact being pivotaily mounted intermediate said two stationary contacts, said movable contact having oppositely facing contact surfaces thereon, said manual means comprising a slidable plunger mounted to extend through and outwardly of said frame means, a spring operative to move said plunger to extend partially outwardly of said frame, plunger guiding means on said frame means, dog means on said plunger guiding means engageable' with said manual means when moved to engage said movable contact to engage said one of said stationary contacts to hold said plunger in its manually moved position, said dog being actuated by said spring-biased movable contact means to release said manual means to move outwardly of said frame means to provide a visual indication of the contact setting of the circuit breaker responsive to overload in said one external circuit.

2. An electrical circuit breaker comprising a frame structure having mounted thereon two spaced stationary electrical contacts, a pivoted contact arm having an oppositely facing electrical contact means thereon, said contact arm being pivoted intermediate said pair of stationary contacts,-said oppositely facing contact means on said pivoted arm contacting and limiting the pivotal movement of said arm by said stationary contacts, said stationary contacts and said pivoted contact a'rmand said oppositely facing contact means comprising portions of two separate external circuits, resilient means biasing said pivoted contact-carrying arm in one direction thereby tending to close one external circuit, latch means engageable with the free end of said pivoted contact arm, said latch means when'engaged with said pivoted contact maintaining the contact carried thereby in engagement with tone of said stationary contacts to complete the'circuit in one of said external circuits, electromagnetic means including a movable armature, said'electromagnetic means having an ener gizing coil comprising a part of one of said external circuits, said armature moving said latch means to disengage said pivotal contact arm on occurence of a predetermined overload in said one external circuit to open said circuit, said resilient means moving said pivoted contact arm to engage said contact carried thereby with the other of said external circuits to energize said other circuit, said other circuit comprising an electrical indi cator means as to the condition of said first circuit, a hollow cylinder mounted in a wall of said frame and extending therethrough, a plunger slidably mounted in said hollow cylinder and having a head at its inner end and manually engageable means at its opposite end, resilient means biasing said plunger toward a position outwardly of said frame, said hollow cylinder having means at its inner end to support a pivoted latching dog thereon, said latching dog engageable with means on said plunger to releasably latch said plunger in its innermost position, means limiting the slidable movement of said plunger in both directions of its sliding movement, said pivoted contact arm having an abutment thereon engageable with said latching dog when said pivoted contact arm is released by said movable armature and pivoted by said resilient means s to release said slidable plunger for movement to its outermost position by its said resilient means to visually indicate the position of the pivoted contact arm relative to said one stationary contact.

3. An electrical circuit breaker comprising a frame structure having mounted thereon two spaced stationary electrical contacts, a pivoted contact arm having an o spositely facing electrical contact means thereon, said contact .rm being pivoted intermediate said pair of stationary contacts, said oppositely facing contact means on said pivoted arm contacting and limiting the pivotal movement or" said arm by stationary contacts, said stationary contacts and said pivoted contact arm and said oppositely facing contact means comprising portions of two separate external cir cuits, resilient means biasing said pivoted contact-carrying arm in one direction, thereby tending to close one external circuit, latch means engageable with the free end of said pivoted contact arm, said latch means when engaged with said pivoted contact maintaining the contact carried thereby in engagement with one of said stationary contacts to complete the circuit in one of said external circuits, electromagnetic means including a movable armature, said electromagnetic means having an energizing coil comprising a part of one of said external circuits, said armature moving said latch means to disengage said pivotal contact arm on occurrence of a predetermined overload in said one external circuit to open said circuit, said resilient means moving said pivoted contact arm to engage said contact carried thereby with the other of said external circuits to energize said other circuit, said other circuit comprising an electrical indicator means as to the condition of said first circuit, a hollow cylinder mounted in a Wall of said frame and extending therethrough, a plunger slidably mounted in said hollow cylinder and having a head at its inner end and manually engageable means at its opposite end, resilient means biasing said plunger toward a position outwardly of said frame, said hollow cylinder having means at its inner end to support a pivoted latching dog thereon, said latching dog e-ngageable with means on said plunger to releasably latch said plunger in its innermost position, means limiting the slidable movement of said plunger in both directions of its sliding movement, said pivoted contact arm having an abutment thereon engageable with said latching dog when said pivoted contact arm is released by said movable armature and pivoted by said resilient means to release said slidable plunger for movement to its outermost position by its said resilient means to visually indicate the position of the pivoted contact arm relative to said one stationary contact, said one stationary contact being mounted on a slightly resilient arm fixed on said frame, said resilient arm forming a resilient support for said one stationary contact, said slightly resilient arm and contact thereon being slightly movable by the pressure of said pivoted contact thereagainst when said pivoted contact is moved by said manually movable plunger into engagement therewith, said one stationary contact remaining in engagement with said movable contact arm during the initial movement of said pivoted contact in the direc tion of the bias of the resilient means of said pivoted contact arm when manual pressure is removed from said plunger.

4. An electrical circuit breaker comprising a supporting frame having mounted thereon two spaced coplanar stationary contacts, a pivoted arm intermediate said stationary contacts, said pivoted arm having a contact means thereon engageable with either of said stationary contacts at the ends of the pivotal movement thereof, two external circuits, the pivoted contact and either of said stationary cont-acts forming portions of said two separate external circuits, spring means biasing said movable contact away from one of said stationary contacts and towards the other one, electromagnetic means including a coil and pivoted armature, said coil forming a part of the external circuit connected to said one of said contacts,

spring-biased pivoted latch means engageable with the end of said pivoted contact arm to maintain engagement between said one stationary contact and said pivoted contact, said latch being disengageable from said pivoted cont-act arm when a predetermined amount of overload in the external circuit including said one stationary contact obtains, said spring means moving said pivoted arm and its contact means away from said one stationary contact when said pivoted arm is released from said pivoted latch and moving the contact means on said pivoted arm into en agement with the other stationary contact, said other contact forming part of an indicator external circuit indicating the condition of the other external circuit, said one stationary contact being mounted on a slightly resilient arm fixed on said frame, said slightly resilient arm providing a slightly yieldable mounting for said one stationary contact, said frame having manually operable eans thereon to move said contact means on said pivoted arm into engagement with said one stationary contact, said pivoted latch having a lip with a camming surface thereon whereby as said pivoted contact arm is moved by said manually operable means the end of said pivoted latch is caused to move in the same plane and initially downwardly away from the pivoted contact arm against its said spring bias and then b ck into engagement with said arm to maintain engagement between said one stationary contact and said contact means on said pivoted arm, said resilient mounting of said one stationary contact efifective to maintain engagement of said one stationary contact and said pivoted arm contact means during an initial slight return movement of said pivoted contact arm when manual pressure is initially removed from said manually operable means.

5. An electrical circuit breaker comprising a supporting frame having mounted thereon two spaced coplanar stationary contacts, a pivoted arm intermediate said stationary contacts, said pivoted arm having a contact means thereon engaegable with either of said stationary contacts at the ends of the pivotal movement thereof, two external circuits, the pivoted contact and either of said stationary contacts forming portions of said two separate external circuits, spring means biasing said movable contact away from one of said stationary contacts and towards the other one, electromagnetic means including a coil and pivoted armature, said coil forming a part of the external circuit connected to said one of said contacts, spring-biased pivoted latch means engageable with the end of said pivoted contact arm to maintain engagement between said one stationary contact and said pivoted contact, said latch being disengageable from said pivoted contact arm when a predetermined amount of overload in the external circuit including said one stationary contact obtains, said spring means moving said pivoted arm and its contact means away from said one stationary contact when said pivoted arm is released from said pivoted latch and moving the contact means on said pivoted arm into engagement with the other stationary contact, said other contact forming part of an indicator external circuit indicating the condition of the other external circuit, said one stationary contact being mounted on a slightly resilient arm fixed on said frame, said slightly resilient arm providing a slightly yieldable mounting for said one stationary contact, said frame having manually operable means thereon to move said contact means on said pivoted arm into engagement with said one sta tionary contact, said pivoted latch having a lip with a carnming surface thereon whereby as said pivoted cont act arm is moved by said manually operable means the end of said pivoted latch is caused to move in the same plane and initially downwardly away from the pivoted con-tact arm against its said spring bias and then back into engagement with said arm to maintain engagement between said one stationary contact and said contact means on said pivoted arm, said resilient mounting of said one stationary contact effective to maintain engagement of said one stationary contact and said pivoted arm contact means during an initial slight return movement of said pivoted cont-act arm when manual pressure is' initially removed from said manually operable means, said manually operable means extending through a wall at one end of said frame, a casing sealingly enclosing all other sides of said frame, terminal means on said casing and electrical connections between each of said pivoted and stationary contacts with said terminal means.

6. An electrical circuit breaker comprising a supporting frame having mounted thereon two spaced coplanar stationary contacts, a pivoted arm intermediate said stationary cont acts, said pivoted arm having a contact means thereon engageable with either of said stationary contacts at the ends of the pivotal movement thereof, two external circuits, the pivoted contact and either of said stationary contacts forming portions of said two separate external circuits, spring means biasing said m-ovable contact away from one of said stationary contacts and towards the other stationary contact, electromagnetic means including a coil and pivoted armature, said coil forming a part of the external circuit connected to said one of said contacts, spring-biased pivoted latch means engageable with the end of said pivoted contact arm to maintain engagement between said one stationary contact and said pivoted contact, said latch being disengageable from said pivoted contact arm when a predetermined amount of overload in the external circuit including said one stationary contact obtains, said spring means moving said pivoted arm and its contact means away from said one stationary contact when said pivoted arm is released from said pivoted latch and moving the contact means on said pivoted arm into engagement with the other stationary contact, said other contact forming part of an indicator external circuit indieating the condition of the other external circuit, said one stationary contact being mounted on a slightly resilient arm fixed on said frame, said slightly resilient arm providing a slightly yieldable mounting for said one stationary contact, said frame having manually operable means thereon to move said contact means on said pivoted arm into engagement with said one stationary contact,"said pivoted latch having a lip with a camming surface thereon whereby as said pivoted contact arm is moved by said manually operable means the end of said pivoted latch is caused to move in the same plane and initially downwardly away from the pivoted contact arm against its said spring bias and then back into engagement with said arm to maintain engagement between said one stationary contact and said contact means on said pivoted arm, said resilient mounting of said one stationary contact effective to maintain engagement of said one stationary contact and said pivoted arm contact means during an initial slight return movement of said pivoted contact arm when manual pressure is initially removed from said manually operable means, said manually operable means extending through a wall at one end of said frame, a casing sealingly enclosing all other sides of said frame, terminal means on said casing and electrical connections between each of said pivoted and stationary contacts with said terminal means, said manually operable means comprising a plunger and having guide means therefor including a dog latch means thereon to latch said plunger in position when moved inwardly of said frame to establish engagement between said one stationary contact and said pivoted arm contact, spring means biasing said manually operable plunger outwardly of said frame, said pivoted contact arm being operative to actuate said dog latch to release said manual plunger to move partially outwardly of said frame when said overload occurs, said plunger thereby comprising a mechanical indicator as to the condition of the circuits controlled by said circuit breaker.

7. A circuit breaker comprising a mounting frame, two arms fixedly mounted on said frame in a given plane,

10 one of said arms being slightly resilient, an electrical contact on the end of each of said arms in facing relation, a pivoted arm mounted intermediate said stationary contacts having a contact thereon engageable with either stationary contact at the ends of its pivotal movement, means to move said pivoted contact into engagement with said resiliently mounted stationary contact, latch means directly engageable with said pivotedcontact :arm to maintain said pivoted contact in engagement with said one resiliently mounted stationary contact, the resilient mounting of said one stationary contact maintaining engagement between said one stationary contact and said pivoted contact during a predetermined initial portion of the movement of said pivoted contact away from said one statioanry contact, abutment means being provided on the free end of said pivoted arm, manually operable contact-setting means movably mounted in and extending from said mounting frame, said contact-setting means having means thereon engageable with said abutment means .to engage said pivoted :arm cont-act with said contact arm on said slightly resilient arm to resiliently defiect said resilient arm and bodily move both said cont acts while engaged through a predetermined portion of the pivoted movement in both directions of said pivoted arm by said manually operable means,

8. The circuit breaker as defined in claim 7 wherein said manually operable contact-setting means comprises a slidably mounted plunger, spring means biasing said plunger outwardly ofsaid mounting frame, dog latch means latching said plunger in position when manually moved inwardly of said mounting frame against the action of said spring means after said plunger has established engagement between the contacts on said pivoted arm and resilient arm, said pivoted contact arm being operative to actuate said dog latch means to rel-ease said plunger for outward movement relative to said mounting frame when said contacts on said pivoted arm and said resilient arm are opened by overload conditions in said circuit breaker.

9. An electrical circuit breaker comprising a frame structure having two spaced stationary contact means mounted thereon, .a pivoted contact means mounted in operative relation to said two spaced stationary contact means, spring means biasing said pivoted contact means solely in one direction, manual means to move said pivoted contact means in the opposite direction, means connecting said two spaced stationary contact means with two external circuits, said pivotal contact means being common to both external circuits, said spaced stationary contact means being engageable by and forming stop means for said pivoted contact means at each end of its pivotal movement, pivoted latch means engageable with the free end of said pivoted contact means, said latch means when engaged with said pivoted contact means maintaining it in electrical contact with one of said stationary contact means, motor means operable by a predetermined excess loading in one of said two external circuits to actuate said latch means to release said pivoted contact means, said spring means thereupon moving said pivoted contact means to open said one of said external circuits and close the other of said circuits, manually operable plunger means slidably mounted in one end of said frame for effecting engagement between said pivoted contact means and said one stationary contact means when said plunger is manually moved inwardly of said frame, spring means biasing said plunger for movement outwardly of said frame, dog latch means latching said slidable plunger inwardly of said frame structure against the bias of said spring means after engagement of said contacts by said plunger, said motor means and said plunger means both lying in substantial axial alignment, casing means sealingly closing said frame sides and end opposite said one end.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Moore 200-89 Scheril 200-87 Persons 200106 Guler 200-87 Finch 200-111 Martin-Hurst 200-87 Wilson 200-106 12 2,591,336 4/52 Bordelon 200-87 2,877,569 3/59 Eisenberg ZOO-87 3,005,890 10/61 White et a1. 200--111 FOREIGN PATENTS 1,171,980 10/58 France.

BERNARD A. GILHEANY, Primary Examiner.

MAX L, LEVY, Examiner. 

1. AN ELECTRICAL CIRCUIT BREAKER COMPRISING FRAME MEANS HAVING MOUNTED THEREON PLURAL STATIONARY CONTACT MEANS, A MOVABLE CONTACT MEANS, SPRING MEANS BIASING SAID MOVABLE CONTACT MEANS IN ONE DIRECTION, MANUAL MEANS TO MOVE SAID PIVOTED CONTACT MEANS IN THE OPPOSITE DIRECTION TO ENGAGE ONE OF SAID STATIONARY CONTACTS, SAID PLURAL STATIONARY CONTACT MEANS ENGAGEABLE BY AND FORMING STOP MEANS FOR SAID MOVABLE CONTACT MEANS AT EITHER END OF ITS MOVEMENT, MEANS CONNECTING SAID STATIONARY AND MOVABLE CONTACT MEANS WITH TWO EXTERNAL CIRCUITS SAID STATIONARY AND MOVABLE CONTACT MEANS OPERATIVE TO OPEN AND CLOSE SAID TWO EXTERNAL CIRCUITS, LATCH MEANS SPRING BIASED IN ONE DIRECTION AND ENGAGEABLE WITH SAID MOVABLE CONTACT MEANS AT ONE END OF ITS MOVEMENT, MOTOR MEANS IN ONE OF SAID EXTERNAL CIRCUITS, SAID LATCH MEANS BEING RESPONSIVE TO OVERLOAD IN THE MOTOR MEANS TO RELEASE SAID MOVABLE CONTACT MEANS TO OPEN SAID ONE CIRCUIT, SAID BIASING MEANS MOVING SAID MOVABLE CONTACT MEANS WHEN RELEASED TO CLOSE THE OTHER OF SAID CIRCUITS, SAID MOTOR MEANS AND SAID MOVABLE AND PLURAL STATIONARY CONTACT MEANS AND SAID MANUAL MEANS ALL LYING IN SUBSTANTIAL AXIAL ALIGNMENT, SAID MOVABLE CONTACT B EING PIVOTALLY MOUNTED INTERMEDIATE SAID TWO STATIONARY CONTACTS, SAID MOVABLE CONTACT HAVING OPPOSITELY FACING CONTACT SURFACES THEREON, SAID MANUAL MEANS COMPRISING A SLIDABLE PLUNGER MOUNTED TO EXTEND THROUGH AND OUTWARDLY OF SAID FRAME MEANS, A SPRING OPERATIVE TO MOVE SAID PLUNGER TO EXTEND PARTIALLY OUTWARDLY OF SAID FRAME, PLUNGER GUIDING MEANS ON SAID FRAME MEANS, DOG MEANS ON SAID PLUNGER GUIDING MEANS ENGAGEABLE WITH SAID MANUAL MEANS WHEN MOVED TO ENGAGE SAID MOVABLE CONTACT TO ENGAGE SAID ONE OF SAID STATIONARY CONTACTS TO HOLD SAID PLUNGER IN ITS MANUALLY MOVED POSITION, SAID DOG BEING ACTUATED BY SAID SPRING-BIASED MOVABLE CONTACT MEANS TO RELEASE SAID MANUAL MEANS TO MOVE OUTWARDLY OF SAID FRAME MEANS TO PROVIDE A VISUAL INDICATION OF THE CONTACT SETTING OF THE CIRCUIT BREAKER RESPONSIVE TO OVERLOAD IN SAID ONE EXTERNAL CIRCUIT. 